15 Answers
15

If you are like me and don't like to install additional software to fix a problem like this, I'd go with XQYZ's suggestion and use robocopy to solve the problem. (In my case the problem was created by robocopy in the first place, by copying a directory which had recursive junction points in it without supplying /XJ to robocopy).

To delete the directory tree starting at c:\subdir\more\offending_dir:

The total step-by-step-process is as simple as this:

cd c:\subdir\more to cd into its parent directory.

mkdir empty to create an empty directory.

robocopy empty offending_dir /mir to mirror the empty directory into the offending one.

After some waiting you're done! Finish it up with:

rmdir offending_dir to get rid of the now empty offending directory and

This is actually quite simple to fix. Say that the directory structure is as such:

C:\Dir1\Dir1\Dir1\Dir1…

To fix it, just rename each folder to a one-character folder-name until it is no longer too long to delete:

Rename C:\Dir1 to C:\D

Navigate to C:\D\

Rename C:\D\Dir1 to C:\D\D

Navigate to C:\D\D\

Goto 1 until total length of path is <260

Here’s a batch file to automate the process (this simple version is best for simple directories like the one described in the question, especially for disposable ones). Pass it the highest folder possible (eg C:\Dir1 for C:\Dir1\Dir1\Dir1… or C:\Users\Bob\Desktop\New Folderfor C:\Users\Bob\Desktop\New Folder\abcdefghi…)

@echo off
if not (%1)==() cd %1
for /D %%i in (*) do if not %%i==_ ren "%%i" _
pushd _
%0
popd

Technical Explanation

The other proposed solutions are backwards; you can’t fix it by working your way from the innermost directory outward, you need to go in the other direction.

When you try to access a directory, you do so using its absolute path whether explicitly or not, which includes everything that came before it. Therefore, for a directory structure like C:\Dir1\Dir1\Dir1\Dir1, the length of the path to the innermost Dir1 is 22. However the length of the path to the outermost Dir1 is only 7, and therefore is still accessible regardless of its contents (in the context of a given directory’s path, the file-system has no knowledge of what it contains or the effect it has on the total path length of its child directories; only its ancestor directories—you cannot rename a directory if the total path-length will be too long).

Therefore, when you encounter a path that is too long, what you need to do is to go to the highest level possible and rename it to a one-character name and repeat for each level therein. Each time you do so, the total length of the path shortens by the difference between the old name and new name.

The opposite is true as well. You cannot create a path that is greater than the maximum supported length (on DOS and Windows, MAX_PATH = 260). However, you can rename directories, working from the innermost outward, to a longer name. The result is that deeper folders whose absolute path is >260 will be inaccessible. (That does not make them “hidden” or secure, since they are simple enough to get at, so don’t use this method to hide files.)

Interesting Side Note

If you create folders in Windows 7 Explorer, it may seem like Explorer allows you to create subdirectories such that the total length is longer than MAX_PATH, and in effect it is, however it is actually cheating by using “DOS 8.3 filenames”. You can see this by creating a tree such as the following:

It is 696 characters long, which of course is much longer than 260. Further, if you navigate to the innermost subdirectory in Explorer, it shows it as expected in the address bar when it is not in focus, but when you click in the address bar, it changes the path to C:\ABCDEF~1\ABCDEF~1\ABCDEF~1\ABCDEF~1\ABCDEF~1\ABCDEF~1\ABCDEF~1\ABCDEF~1\ABCDEF~1\ABCDEF~1\ABCDEF~1\, which is only 102 characters long.

In XP, it does not do this, instead it steadfastly refuses to create a longer path than is supported.

What would really be interesting is to find out how Windows 7 Explorer handles “too-long paths” when the NtfsDisable8dot3NameCreation option is set.

It is possible to create a path longer than MAX_PATH, as explained here. Unfortunately, \\?` doesn't work with rmdir`.
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grawityMar 11 '11 at 18:35

@grawity, yes, but that is because it works under the same principal: a short path is renamed to a longer one; that just does it dynamically by expanding a variable as opposed to manually renaming it to la onger one. It is not possible to create a directory whose absolute path is too long when the creation command has enough information to determine the total length.
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SynetechMar 11 '11 at 19:31

2

@Synetech: No, it works differently. Paths like \\?\C:\dir\dir\dir\dir literally bypass MAX_PATH; there are no "variables" involved. (But like I said, it does not work with rmdir or other cmd.exe builtins for some reason.)
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grawityMar 11 '11 at 19:35

eg, try running md C:\01234567890123456789012345678901234567890123456789012345678901234567890123456‌​789012345678901234567890123456789012345678901234567890123456789012345678901234567‌​890123456789012345678901234567890123456789012345678901234567890123456789012345678‌​901234567890123456789 It won’t work because the file-system has sufficient information to determine that the total path length would be 263 characters, so it fails.
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SynetechMar 11 '11 at 19:35

1

(Also, don't confuse the path length with component length. You cannot have a single directory with a name over 255 characters; however, you can have a path much longer than that.)
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grawityMar 11 '11 at 19:37

Nope; that first command won’t work if the directory is too long; it will return the error Invalid parameter.
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SynetechSep 8 '11 at 5:30

2

@Synetech, sure, but if you subst just C:\TEMP\dir1\dir1\dir1, then it will shorten part of it, thus allowing you to get in. It is just like your suggestion of renaming, but with mapping instead. ;)
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BobsonNov 21 '11 at 2:59

I wrote a small C# app to help me delete a similar very deep structure generated by a careless usage of Robocopy and a backup from Homeserver; by default Robocopy treats joint points as regular folders... :-( You might end up with a big mess without noticing it.

The tool is available at CodePlex with source files, for anyone to use.

While working with Sikuli I got jacked with a Calculator.sikuli recursion loop in the program that made an uncountable amount of "calculator.sikuli.calculator.sikuli" dirs.
I could move the tree, but pathname too long to delete.

After trying several solutions with popd loop, Scandisk and getting (perceptibly) nowhere....

I wrote this script to 'go deep' into the recursed dirs(in a dir called 'a'), move them(to a dir called 'b'), then delete the truncated tree, move them back(to 'a'), and repeat:

Some time ago I created a small, self-contained utility executable called DeleteFiles that you can use to perform this task easily.

Using this self-contained, utility you can simply do:

deletefiles c:\yourfolder\subfolder\*.* -r -f

to delete the entire folder structure. -r recurses the folder hierarchy from the starting directory down, -f deletes any folders that are empty (which will be all of them if you use . as the filespec). DeleteFiles supports paths longer than the Windows MAX_PATH limit so it will work just fine on deeply nested folders.

DeleteFiles is free and open source and you can grab either the binary or source code from GitHub or install directly using Chocolatey

Yes, but like I said, you have to work from the outside in, otherwise it won’t work.
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SynetechSep 8 '11 at 5:33

Of course. I've generally found the longest folder names tend to be the first (in patch folders) or the last. Most of the time, you only need to change one or two folder names to get it to the right length.
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music2myearSep 8 '11 at 14:31

Yes, but if you start with the innermost one, it will not work because the ren command will fail with path too long.
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SynetechSep 8 '11 at 21:09

1

Yes, the scripts provided above are a clever and effective method of handling this problem automatically. It has only happened to me a few times and so I've simply used the manual rename process. To do that I simply start renaming the folder structure wherever I happen to be at in the offending tree, and my experience is the longest folder names appear more often at the beginning or the end of the tree structure. My answer is therefore a valid one, though probably not the strongest or cleverest here. It's not worth a downvote.
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music2myearSep 9 '11 at 14:00

> I simply start renaming the folder structure wherever I happen to be at in the offending tree Well, yes, if you are already inside the tree, then you can certainly rename at least that folder (you’ll need to go to its parent); you may be able to rename a subfolder as well, but it may be too long.
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SynetechSep 10 '11 at 16:57

I had the same problem, except it was created by a recursive Cobian Backup task. I turns out the free Cobian software includes a Deleter application that can easily remove these pesky nested folders super quickly.